Rhodesian ridgeback mix?

I am considering adopting a rhodesian ridgeback mix...at least that is what they think it is. I have done a bit of research on this type of dog, and am having second thoughts. I have a son who is 7, a gentle boy, and wonder if this type of dog would be good for my child. The dog is one year old, and housebroken...so I am told. I plan to crate him while I work. I work midnights, 12 hour shifts, I plan to walk him 2x daily...and let him play in the backyard, which is not big, but average. Thank you.